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Mesa/Boogie Triple Rectifier Loop fault

1/28/2006 12:25 AM
Peter	Mesa/Boogie Triple Rectifier Loop fault Hi Guys Have a problem in the selectable loop section of a Mesa Triple Rectifier. Have emailed International support but bounced and tried ringing service (twice) and left a message on their answering machine but no reply/response. Well I'll keep on trying to contact somebody but in the meantime here is a fault discription. When the loop select switch is in any other position than bypass there is a very noticable top end/treble roll off. The switch is noisy whilst rotating - obvious dullish clicking (clunking). There seems to be aprox 1v DC across the send pot regardless where the wiper is. I'm suspecting leaky bypass cap or maybe the LM 3914 which appears to be the relay driver. I am hoping for a schematic of that section before cutting/sucking out the chip ..everything else works fine If the loop is not used. The guy who owns it has picked it up 'till I can get a schematic or find a cure. It was imported privately thus not good form to approach the local importers/agents. Hope some bright spark has encountered this before... Cheers Peter

1/28/2006 12:25 AM

Peter

Mesa/Boogie Triple Rectifier Loop fault

Hi Guys
Have a problem in the selectable loop
section of a Mesa Triple Rectifier.
Have emailed International support but bounced
and tried ringing service (twice) and left a
message on their answering machine but no
reply/response.
Well I'll keep on trying to contact somebody
but in the meantime here is a fault discription.
When the loop select switch is in any other position than bypass there is a very noticable
top end/treble roll off. The switch is noisy whilst rotating - obvious dullish clicking (clunking).
There seems to be aprox 1v DC across the send pot regardless where the wiper is.
I'm suspecting leaky bypass cap or maybe the LM 3914 which appears to be the relay driver.
I am hoping for a schematic of that section
before cutting/sucking out the chip ..everything
else works fine If the loop is not used.
The guy who owns it has picked it up 'till
I can get a schematic or find a cure.
It was imported privately thus not good form to approach the local importers/agents.
Hope some bright spark has encountered this
before...
Cheers
Peter